Table 1.
Clinical sensitivity of the evaluated methods for detecting blaKPC in rectal surveillance swabs
| Swab testing method | No. of positive swabs/total no. of swabs | Sensitivity (% [95% confidence interval])c |
|---|---|---|
| Direct PCRa | 46/46 | 100 (92.3–100) |
| Broth-enriched PCRa | 46/46 | 100 (92.3–100) |
| CDC methodb | 36/46 | 78.3 (64.4–78.7) |
| HardyCHROM ESBL agarb | 35/46 | 76.1 (62.11–86.1) |
a
Five swabs with the D-PCR and 3 swabs with the BE-PCR with visible soiling were negative on initial testing, but were positive on retesting after nucleic acid extraction on the MagNA Pure Compact system.
b
For the CDC method, blaKPC and blaNDM PCR was performed on all morphologically distinct colonies. For the HardyCHROM ESBL agar method, PCR was performed on carbapenem-resistant isolates. A specimen was considered positive if any isolate from that specimen was blaKPC positive by PCR.
c
McNemar's test D/BE-PCR versus HC-A, P = 0.0009; D/BE-PCR versus CDC-A, P = 0.0016; CDC-A versus HC-A, P = 0.76.